For the most part, low turnout in southeastern Pennsylvania — especially in urban Philadelphia — devastated Specter’s hopes of reelection, despite his having the backing of organized labor, the state party and, for a while at least, the White House in his first bid for Senate as a Democrat.

“It’s been a great privilege to serve the people of Pennsylvania,” Specter said with a pained voice to a small but appreciative audience that chanted his first name at the beginning and end of his remarks at his election night headquarters.

Standing alongside his wife, Joan, and speaking slowly, Specter thanked his supporters, including President Barack Obama. He said of Sestak, “I will support him in the election.”

Sestak will take on the other Senate primary victor Tuesday evening, former Rep. Pat Toomey (R-Pa.), a fiscal conservative who once headed the Club for Growth.

A relative newcomer, in the House since 2006, Sestak has the kind of resume national Democrats are looking for — a former Navy admiral who saw action in Afghanistan. Democrats quickly closed ranks and declared Sestak the kind of outsider who voters are looking for this fall.

“Joe Sestak has a compelling life story and a powerful message of change. He knows what is wrong with Washington and, if elected to the Senate, will shake up how business is done in the Capitol,” said Sen. Robert Menendez (D-N.J.), who heads the Senate Democratic campaign arm.

Moments later, Menendez issued a memo, calling Sestak “a former naval officer who has proven he takes a back seat to nobody when it comes to shaking up Washington and taking on the establishment. Joe, an energetic campaigner, has a compelling personal profile and a message of change that resonates with voters, especially in this political environment.”

At one point, the race seemed Specter’s to lose, with sky-high name recognition in a state where he served for three decades. But he was a fixture in Washington politics at a time when that was toxic. And as primary day approached, Obama and Vice President Joe Biden — both of whom had boasted of luring the longtime Republican into the Democratic ranks last year — steered well clear of the state and Specter himself.

The White House rebuffed an 11th-hour plea from Specter for a presidential visit on his behalf. Biden was in Philadelphia Monday night to give a commencement speech but did not make a campaign appearance for his longtime friend in the Senate.

In the Philadelphia suburbs of Montgomery County, state Rep. Josh Shapiro (D) said he had noted more enthusiasm for Sestak than Specter.

“I can just tell you more anecdotally, just around Montgomery County today, there seemed to be a lot more energy today around the Sestak campaign,” said Shapiro, who is neutral in the Senate race.

In defeating Specter, Sestak unseated one of the most recognizable U.S. senators, a formidable former prosecutor who survived two bouts with cancer. He rose to national prominence as a Republican member of the Senate Judiciary Committee, who drew notice — and, to this day, anger from some women’s groups and Democrats — for his tough questioning of Anita Hill in the Clarence Thomas Supreme Court confirmation hearings.

He was one of only three Republicans to vote for Obama’s stimulus bill in early 2009, and shortly thereafter — after heavy entreaties from Biden — Specter made the party switch, effectively acknowledging the difficulty of holding onto his Senate seat in a state that has been trending Democratic in recent elections.

Although Specter led Sestak in public polls during most of the race, the two-term congressman climbed back in the polls in the last few weeks of the race once he started airing television advertisements. In particular, Sestak’s campaign put up a spot in heavy statewide rotation that showed Specter alongside former President George W. Bush and former Alaska Gov. Sarah Palin.

Although Specter boasted a 30-point lead among Philadelphia voters, Sestak won with strong turnout in the collar counties around the city. Sestak won every one of the five suburban counties surrounding Philadelphia with double-digit margins except Montgomery County. Ironically, Specter used to count on Republicans in that same region to win the GOP nomination and general election in his previous bids.

In the final weeks of the election, Democratic leaders in Pennsylvania and Specter supporters emphasized that Specter would be a more formidable general election candidate than Sestak. After all, they said Specter had a proven track record of crossover appeal when he ran for reelection as a Republican.

“I think Joe Sestak would have more building to do than Specter in the general election,” said former Rep. Phil English (R-Pa.). “The Sestak campaign concentrated on bringing on board a Democratic constituency and hasn’t had to reach beyond it. I think that Joe Sestak would have to seriously reposition himself in the fall for the general election.”

And in the also populous southwestern part of the state, campaign operatives said turnout was marginally better than in the Philadelphia area. That was a good sign for Sestak, according to Pennsylvania Democrats’ Southwestern Caucus Chairman John Hanna.

Sestak won Allegheny County, which is the most populous county in southwestern Pennsylvania, by 4 points. The slightly higher turnout in western Pennsylvania also likely boosted Allegheny County Executive Dan Onorato’s bid for governor, although polls showed him leading the crowded Democratic primary field by double digits until Election Day. Onorato won the Democratic nomination on Tuesday evening, while Attorney General Tom Corbett captured his bid for governor in a crowded GOP primary field as well.

And while Specter might have fallen Tuesday evening, House incumbents with primary challenges won reelection by sizable margins. Rep. Paul Kanjorski (D-Pa.) staved off a spirited challenge from Lackawanna County Commissioner Corey O’Brian, 49 to 36 percent. Rep. Tim Holden (D-Pa.) also defeated his primary challenger, attorney Sheila Dow-Ford, by a two-to-one margin.

Attorney Keith Rothfus easily defeated a GOP candidate who was once touted as a top recruit by the national party, former U.S. Attorney Mary Beth Buchanan, 67 percent to 33 percent, and will face Rep. Jason Altmire (D-Pa.) this November.

In two other potentially competitive House districts, businessman Mike Kelley (R) was the front-runner and former U.S. Attorney Tom Marino (R) was the winner in their respective races in the 3rd and 10th House districts.